Prediction Of Pituitary Adenoma Consistency And Analysis Of Relationship Between Consistency And Extent Of Resection Based On Tumor/Cerebellar Peduncle T2-weighted Imaging Intensity Ratio On Preoperative And Postoperative MR Image

【Background】Controversies exist in imaging modalities for predicting adenoma consistency.In this study,we proposed a method of predicting consistency by magnetic resonance T2-sequence imaging based on adenoma to cerebellar peduncle signal(TCTI)ratio.Utilizing postoperative imaging,we sought validation of this method.【Material and Methods】Between January 2013 and May 2017,191 consecutive patients with pituitary adenoma diagnosed at our institution were retrospectively studied.During surgery,a consistency grade was assigned to each lesion by the operating neurosurgeon.Using preoperative and postoperative T2-weighted MRI sequences,TCTI ratio was calculated for each patient.【Results】The median TCTI ratio was 1.55,1.28,and 1.25 for soft,fibrous,and hard adenomas,respectively.The difference were significant for all groups(P<0.001).A cutoff value of 1.38 for soft adenomas was found to be 80.2% sensitive and 88.7% specific.The median ratio of the outermost layer of residual tumor was 1.25(SD±0.408,95%CI 1.27-1.42).It was less than that ratio of the upper,lower quarter,and middle region of adenoma,respectively,and the inter-group differences were all statistically significant with P≤0.001.The extent of resection for the soft group was significantly greater than that of the hard group(85.3% vs 70.6%,P=0.011).Analysis of Variance(ANOVA)revealed that the consistency grade was the influencing factor of degree of resection.P=0.003.【Conclusion】The TCTI ratio showed good correlation with adenoma consistency.Also ratio of the residual adenoma proved it again in our study.This method is quantifiable and reproducible,which helps preoperative surgical planning.